Cutting device



April 1962 v. J. SIGODA 3,029,759

CUTTINGDEVICE Filed Dec. 23, 1959 2 Sheets-Sheet 1 IN VEN TOR. V/cro d.5/500 ,4 rrop/YEy v. J. SIGODA CUT-TING DEVICE April 17, 1962 2Sheets-Sheet 2 Filed Dec. 23, 1959 INVENTOR. Her-04 J. $16004 ATTO/P/YEY i u te EV C Victor J. Sigoda, 61 Old Pond Road, GreatNec-k,N.Y. Fae-a Dee. 23, 1959, seeNQ. 861,536

2 Claims. (Cl. 112-9127) This invention relates to a trimming attachmentfor use with zigzag sewing machines. More particularly, it concerns anattachment adapted to trim away the excess material from the bottomlayer of fabric as an upper decorative" layer such as lace istopStitchedthereto. Such work is known as applique in the trade and is usedtypically in the bodice and skirt portions of such feminineundergarments a'sslips and nightgowns.

In a general way, this attachment performs similarly to that disclosedin the Sigo'da U.S. Patent No. 2,432,545 of December 16, 1947. Thatdevice" also trims the excess'material from the edge of a bottom layer,leaving a small margin extending beyond the stitching. However, becausethe movable cutter is operated upwardly, and because of the bulk of theseparator platform, that trimming attachment is limited in thatit'cannot be used in the production of sharp, reverse points on suchgarments without making a cut in the fabric beyond the point. Since inthe formation of such points, the line of stitching moves off in areverse direction after the excc'ss is trimmed away, the out beyond thepoint is not subsequently covered by the stitching, and this leavesanunsightly cut in the garment.

In" the instant device, this limitation has been overcome by utilizing amovable cutter which operates downwardly against a novel stationaryshear member which is part of a substitute needle-plate. The closeadjacency of the shear edge to the needle hole and the rearrangementofthe cutting action to a point just behind the needle makes possiblethe successful production-of sharp points in such garments;

The instant attachment structurally resembles that disclosed in SigodaU.S. Patent No. 2,472,862 of June 14, 1949. It differs however in twosignificant respects. The earlier attachment was designed to provide ashear action inside the line of stitching so that no margin ofgoodswould be left outside the stitching after completion of the sewing.The instant attachment is arranged to leave a small margin of goodsextending beyond the stitching on completion of'the' sewing:Furthermore, in the attachment of that patent, the cutters were arrangedso that the desired shear action is effective immediately in front ofthe path of vertical reciprocation of the needle in the directionof theline of feed; In the present device, the arrangement is such that theshear action occurs rearwardly beyond the path of needle reciprocation.

Accordingly, it has been an object to provide a trimming attachment foruse with zigzag sewing machines which is capable of producing sharpreverse points with out leaving any cut portion uncovered by thestitching.

With the above and such other objects as may appear in the followingdescription, the invention as applied herein can be best understood byreferring thereto in conjunction with the drawings, in which:

FIG. 1 is a view in perspective taken from the operators left showingthe complete attachment as installed on the sewing machine, the presserfoot having been indicated in broken line;

FIG. 2 is a detail view in perspective, the cover plate of theattachment having been removed, showing how the attachment fits into thethroat-plate cutout of the sewing machine, and showing in particular thenovel combined stationary shear member and needle-plate;

FIG. 3 is a detail view in perspective showing the feed-bar and thefeed-dog mounted thereon; the support States Patent 3,Z59,759P'a'tentedApr. 17, was

2 bracket for the movable cutter member, the operating connectio betweenthesupport bracket and the feeddog, and the operatingrelationship of thecutter members, the stationary shear member having been partly brokenaway;

FIG. 4 is an end sectional w'ew taken from the operators left showingthe driving connection for the feedbar, and also showing the operatingrelationship of the cutter members;

FIG. 5 is a detail view, partly in section, taken on line 5-5 of FIG. 4,showing the drive connection between the feed-dog and the movable cutterbracket; and

FIG. 6 is an eiploded View, in perspective, showing the meansfor'rn'oiiiitingthe movable cutter on its support bracket.

Only so much of the zigzagmachine as is necessary to an understanding ofthe invention is indicated in the drawings; Referring now thereto, thecloth-plate 19' of the sewing machine is provided with a cut-out 11 forthe usual throat-plate which is replaced when the attachmantisinstalled." The standard feed b'ar' 12 is provided with a modified formof feed-dog 14 which carries a stud drive shaft 15 (see FIG. 3) at itsforward end and which extends laterally across the line of stitching.The feeddog is provided with the usual serrated teeth in a series ofrows, the rightmost of which, as seen in FIG. 3, is useful inconjunction with the presser-foot in drawing away the trimmed offeii'cess from the bottom layer of fabric to remove it from the sewingarea to avoid subsequent fouling.

A support plate 16 which carries the cutter elements is installed in'thecut-out 11 after theorigin'al throat-plate is removed. Plate 16 isprovided with a pair of mounting holes 17 positioned to register withthethreaded holes in the machine bed,a'nd twosets of opposed, downwardlyprojecting ears 18, each set of which is designed to act as one bearingsupport for a movable cutter support bracket 19. Each ear of each sethas a clearance hole in register to permit a screw such as thatdesignated 20a in FIG. 3 to be mounted horizontally to provide a pivotalmounting for support bracket 19. Screws 20a are retained in place byround, slotted nuts 2%.

Plate 16 is also provided with an aperture 21 through which the feed-dogand the movable cutter operate, and a second set of holes through whichscrews may be passed to secure a combined stationary cutterandneedleplate member 22 on the upper surface of plate 16 (see FIG. 2).

Member 22 is L-shape in form and is pierced in one leg thereof with anelongated needle opening 24, immedi ately adjacent to one end of which,the edge 25 has been prepared" as a vertical shear face to mate with themovable cuttei'. Preferably this face is provided with a slight back-01frelief on the underside to assist in the shear action; Optionally, thisedge may be faced with a hard, long wearing material such as tungstencarbide, to maintain' the shear edge in cutting condition for a longtime before regrinding.

As best seen in FIG. 6, the movable cutter support bracket 19 is formedlike a square letter C, with bearing hubs 26 formed on the extremitiesof the parallel arms thereof, and with a block 28 formed integrally withthe bridge connecting the parallel arms. Bearing hubs 26 are providedfor the pivotal mounting on screws 20a between the two sets of opposedears 18 on plate 16 mentioned previously. Block 28 is part of the meansfor obtaining the vertical oscillation of bracket 19 which produces thecutting action and is also part of the means for retaining the movablecutter.

Block 28 is formed with a recess 29 in which the feeddog stud shaft 15fits when bracket 19 is mounted in the machine cut-out 11, and avertical slot 30 in which 3 cutter blade 31 is held by means of clampblock 32 and the screw 34 which passes through block 32 and into ahorizontally disposed tapped bore in block 28. The tang of blade 31 ispreferably serrated to provide better gripping action in slot 30 whenscrew 34 is tightened.

Movable cutter blade 31 is hook shape in form, and as may be noted inFIG. 6, the upper portion of this hook slopes to the rear. The face ofthis hook opposite the serrations is prepared as a shear face having ashear edge 35 disposed along the slope mentioned. Shear edge 35cooperates with the shear edge 25 on the stationary cutter member 22.The tang of blade 31 may be adjusted vertically in slot 30 so that thecutting action which takes place as shear edge 35 moves downwardlyagainst shear edge 25, is positioned along the line of stitching at apoint just slightly rearwardly of the needle penetrations as the seam isformed. Because of the rearward slope of shear edge 35, it becomesapparent that the vertical adjustment of blade 31 in the clamp means onsupport bracket 19 will result in shifting the point of engagement ofthe shear edges either forwardly or rearwardly with respect to theneedle penetrations, as desired. By keeping the point of engagement justrearward of the needle penetrations no cutting will occur beyond thepoint being sewn and this production defect is thereby eliminated. 1

When the cutters are assembled on support plate 16, it is desirable toprovide resilient engagement between the shear edges. As seen in FIG. 3,leaf spring 36 is anchored under one of the screws 20a and turning screw3-8 into the tapped hole provided in one of the arms of bracket 19increased the pressure applied on the shear edges by the leaf spring.

When the assembled attachment is to be installed on the sewing machine,support plate 16, with the cutters mounted thereon, is placed into thethroat-plate cut-out 11 with the stud shaft 15 on the feed-dog insertedinto the recess 29 of the movable cutter support bracket 19. A cover orbase plate 39 provided with a cut-out in which member 22 may lie flushwith the surface thereof and through which the feed-dog 14 may alsooperate is installed on the cloth-plate of the machine by means of thestandard countersunk head screws 40 which pass through holes 17 of plate16 and into the existing threaded throat-plate mounting holes in the bedof the machine.

Since the sewing machine is provided with the usual four motion drivefor the feed-bar 12, the feed-dog 14, and stud shaft accordingly, hastwo vertical movements, up and down, and these are transmitted fromshaft 15 to support bracket 19 to operate the movable cutter as thesewing takes place.

In the installation of the attachment, nothing is done to interfere withthe normal operation of the stitch-forming and feed members, and thesefunctions are therefore carried out in the usual manner as the cuttingaction progresses. Since only the downward vertical movement of thefeed-dog is efiective in producing the cutting engagement of the shearmembers, and since this coincides with the interval during which thefeed is not effective to transport the work, the trimming of the surplusfabric from the bottom layer takes place while the work is at rest. Thisprevents bunch ing and wrinkling of the work or choking of the cutterswhich might occur if the cutting action were effective while the workwas in motion.

In order to trim the bottom layer only, some means for separating theplies must be employed. In the mentioned patent, this function isperformed by the platform portion of the stationary cutter designated21a therein. The same function is incorporated into the presser-footshoe in this instance, but since this is a matter well known in the artand which can be accomplished in a variety of ways, and since it is notpart of the invention, it is not detailed either in the drawings or inthis description.

What is claimed is:

1. In combination with a sewing machine having a needle reciprocating ina vertical path, a throat-plate cutout and a modified feed dog having aportion adapted to impart the vertical movements of said feed-dog; asupport plate for a pair of cutting members adapted to be mounted insaid throat-plate cut-out in replacement of the usual throat-plate; amovable cutter pivotally supported on said support plate and adapted tobe rocked about its pivotal mounting by the said vertical movementsimparted by the feed-dog when said support plate is mounted in thethroat-plate cut-out; and a mating stationary cutter mounted on saidsupport plate, said stationary cutter being provided with a transverseelongated needle opening and a shear edge formed adjacent one end ofsaid needle opening, said movable cutter and said stationary cutterbeing so arranged and disposed with respect to each other and to thepath of reciprocation of said needle that said cutters are effective tosever the work at a point beyond the said needle path rearwardly in thedirection of the line of feed.

2. A combined needle-plate and stationary cutter member for use with atrimming attachment adapted to be installed on a sewing machine having aneedle reciprocating in a vertical path and which is provided with acut-out for a throat-plate and which has a modified feeddog adapted toimpart the vertical movements thereof; said attachment comprising asupport plate adapted to fit into said throat-plate cut-out in place ofthe usual throat-plate; a movable cutter pivotally mounted on saidsupport plate adapted to be rocked about its pivotal mounting by thevertical movements imparted by the said feed-dog when the support plateis mounted in the throat-plate cut-out; said combined needle-plate andstationary cutter member being L-shape in form and havingan elongatedneedle hole transversely disposed in one leg thereof and a shear edgeformed adjacent one end of said transverse needle hole, said stationarycutting member being adapted to be mounted on said support plate inmating engagement with said movable cutter and to be arranged so thatthe shear action of said cutters will be effective at a point beyond thesaid needle path rearwardly in the direction of the line of feed.

References Cited in the file of this patent UNITED STATES PATENTS

